<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    div {
        width: 500px;
        height: 500px;
        background-color: orange;
        /* 设置透明度 */
        opacity: 0.7;
    }
</style>
<body>
    <div>
        <img src="./images/phone.png" alt="">
    </div>
</body>
</html>